This invention generally relates to elevator systems and more specifically to a space efficient elevator system including a guide rail mounted machine and a sheave design that accommodates the guide rail.
Elevator systems typically include a car and counterweight that move within a hoistway. Roping couples the car and counterweight and supports them as they move. A motor drives the rope to raise and lower the car. Typically, the car includes a roller assembly that cooperates with a guide rail to guide the car within the hoistway. Traditionally, the motor has been mounted within a machine room disposed at the top of the hoistway.
Idler sheaves disposed on the elevator car, for example, form part of a system of roping for raising and lowering the car along with the counterweight. Roping is threaded through idler sheaves at various location in the system, for example, the elevator car and counterweight. The idler sheaves necessarily take up space within the hoistway and the guide rail extends from the interior surface of the hoistway walls toward the elevator car. Various machine mounting strategies have been proposed but building and safety codes require sometimes expensive devices and controls.
Recently, machine room-less elevator systems have been developed that no longer require a separate machine room. Machine room-less elevator systems were developed in response to consumer demands for simpler, more efficient use of space dedicated to elevator systems. Even with such systems, there still is need to decrease the space occupied by an elevator system.
It is desirable to minimize system expenses to conserve hoistway space and allow for easy installation of the elevator car within the hoistway. Further, buildings typically are not designed to make special accommodations for elevator systems.
For these reasons it is desirable to design an elevator system adaptable to efficiently utilize hoistway space. This invention addresses these needs.